The invention relates to pneumatic tires.
Patent FR-A-1,169,474 describes a pneumatic tire with no bead wire, which includes, at the point of anchoring on the rim, small cord plies, the cords of which are mutually parallel in each ply and are highly inclined with respect to the parallel attachment, the various plies being crossed with each other. The object of this patent is to facilitate the manufacture of the tire by virtue of there being no bead wire, since the need to manufacture a bead wire is thus eliminated. However, production of this tire poses problems since it is difficult to guarantee that its elements are satisfactorily held in place during the building-up, shaping and curing steps, and the finished tire does not allow it to exhibit satisfactory rolling endurance.
Patent Application EP-A-672,547 describes a pneumatic tire with no bead wire, which includes an annular element whose tensile strength is appreciably less than that which would be necessary for a bead wire in a known tire of the same size, and at least two reinforcing plies in contact with or near the annular element, the combination of these plies having a tensile strength at least equal to that which would be necessary for a bead wire in a known tire of the same size. This tire exhibits good rolling endurance.
The object of the invention is to improve this known tire.